First listed various formulations of calculating kanban quantities in wmarhel at Elsmar Cove writes …
The formula for calculating the number of kanban cards in a system for a particular product is:
(Daily Demand x (Run Frequency + Lead Time + Safety Time)) / Container Capacity
Daily Demand = Customer Consumption expressed as # of units
Run Frequency = Frequency which you decide to set-up and produce that item. This is expressed as a unit of time. For a five day work week, running the product every day would equal (1), every third day would equal (3), etc.
Lead Time = Manufacturing lead time (processing time + Set-up time + queue time) + lead time for kanban retrieval expressed as a unit of time.
Safety Time = Allowance for variations in demand and supply, also expressed as a unit of time. Keep as low as possible.
Container Capacity = Number of units per container (# of units in a container is always the same number).
10. World Class Manufacturing has an on-line Kanban Size Calculator that uses the following formula:
Total Required Inventory (TRI) = Weekly Part Usage * Lead-time * Number of locations for stock
# Kanban = TRI / Container Capacity
11. Oracle uses
By default, the standard calculation is:
(C – 1) * S = D * L
- C is the number of kanban cards
- S is the kanban size
- D is the average daily demand
- L is the lead time (in days) to replenish one kanban
12. SAP says …
K = ((RT * AC)/CONT) * (SF + C)
- K numbers of Kanban
- CONT contents per Kanban
- RT replenishment lead time per Kanban
- AC average consumption per time
- SF safety factor
- C constant (default 1)